Large ensemble modeling of the last deglacial retreat of the West Antarctic Ice Sheet: comparison of simple and advanced statistical techniques

Abstract. A 3-D hybrid ice-sheet model is applied to the last deglacial retreat of the West Antarctic Ice Sheet over the last  ∼  20 000 yr. A large ensemble of 625 model runs is used to calibrate the model to modern and geologic data, including reconstructed grounding lines, relative sea-level records, elevation–age data and uplift rates, with an aggregate score computed for each run that measures overall model–data misfit. Two types of statistical methods are used to analyze the large-ensemble results: simple averaging weighted by the aggregate score, and more advanced Bayesian techniques involving Gaussian process-based emulation and calibration, and Markov chain Monte Carlo. The analyses provide sea-level-rise envelopes with well-defined parametric uncertainty bounds, but the simple averaging method only provides robust results with full-factorial parameter sampling in the large ensemble. Results for best-fit parameter ranges and envelopes of equivalent sea-level rise with the simple averaging method agree well with the more advanced techniques. Best-fit parameter ranges confirm earlier values expected from prior model tuning, including large basal sliding coefficients on modern ocean beds.

[1]  Sridhar Anandakrishnan,et al.  Evaluating Marie Byrd Land stability using an improved basal topography , 2014 .

[2]  R. McKay,et al.  Glaciology and geological signature of the Last Glacial Maximum Antarctic ice sheet , 2013 .

[3]  B. Smith,et al.  Marine Ice Sheet Collapse Potentially Under Way for the Thwaites Glacier Basin, West Antarctica , 2014, Science.

[4]  J. Kutzbach,et al.  Material for Transient Simulation of Last Deglaciation with a New Mechanism for Bølling-Allerød Warming , 2009 .

[5]  Thomas Zwinger,et al.  Impact of bedrock description on modeling ice sheet dynamics , 2011 .

[6]  I. Sasgen,et al.  Potential of the solid-Earth response for limiting long-term West Antarctic Ice Sheet retreat in a warming climate , 2015 .

[7]  David Pollard,et al.  A simple inverse method for the distribution of basal sliding coefficients under ice sheets, applied to Antarctica , 2012 .

[8]  R. DeConto,et al.  Retreat of the East Antarctic ice sheet during the last glacial termination , 2011 .

[9]  A. Jenkins,et al.  Strong Sensitivity of Pine Island Ice-Shelf Melting to Climatic Variability , 2014, Science.

[10]  Frank Kauker,et al.  Twenty-first-century warming of a large Antarctic ice-shelf cavity by a redirected coastal current , 2012, Nature.

[11]  David Pollard,et al.  Modelling West Antarctic ice sheet growth and collapse through the past five million years , 2009, Nature.

[12]  David Pollard,et al.  A data-constrained large ensemble analysis of Antarctic evolution since the Eemian , 2014 .

[13]  J. Weertman,et al.  Stability of the Junction of an Ice Sheet and an Ice Shelf , 1974, Journal of Glaciology.

[14]  Catherine Ritz,et al.  Modeling the evolution of Antarctic ice sheet over the last 420,000 years: Implications for altitude changes in the Vostok region , 2001 .

[15]  D. Pollard,et al.  Thwaites Glacier grounding-line retreat: influence of width and buttressing parameterizations , 2014, Journal of Glaciology.

[16]  D. Wiens,et al.  The crustal thickness of West Antarctica , 2014 .

[17]  Stewart S. R. Jamieson,et al.  Antarctic palaeo-ice streams , 2012 .

[18]  Klaus Keller,et al.  An assessment of key model parametric uncertainties in projections of Greenland ice sheet behavior , 2012 .

[19]  R. McKay,et al.  Retreat history of the Ross Ice Sheet (Shelf) since the Last Glacial Maximum from deep-basin sediment cores around Ross Island , 2008 .

[20]  J. Annan,et al.  Quantification of the Greenland ice sheet contribution to Last Interglacial sea level rise , 2012 .

[21]  Eric Rignot,et al.  Spatial patterns of basal drag inferred using control methods from a full‐Stokes and simpler models for Pine Island Glacier, West Antarctica , 2010 .

[22]  John B. Anderson,et al.  Reconstruction of changes in the Amundsen Sea and Bellingshausen Sea sector of the West Antarctic Ice Sheet since the Last Glacial Maximum , 2014 .

[23]  Murali Haran,et al.  Improving Ice Sheet Model Calibration Using Paleoclimate and Modern Data , 2015, 1510.01676.

[24]  Eric Rignot,et al.  Inversion of basal friction in Antarctica using exact and incomplete adjoints of a higher‐order model , 2013 .

[25]  A. Timmermann,et al.  Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation , 2014, Nature.

[26]  N. Golledge,et al.  Dynamics of the last glacial maximum Antarctic ice-sheet and its response to ocean forcing , 2012, Proceedings of the National Academy of Sciences.

[27]  John B. Anderson,et al.  Ross Sea paleo-ice sheet drainage and deglacial history during and since the LGM , 2014 .

[28]  Bruno Hamelin,et al.  Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago , 2012, Nature.

[29]  Richard B. Alley,et al.  Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure , 2015 .

[30]  C. Schoof.  Ice sheet grounding line dynamics: Steady states, stability, and hysteresis , 2007 .

[31]  Thomas Zwinger,et al.  A three-dimensional full Stokes model of the grounding line dynamics: effect of a pinning point beneath the ice shelf , 2011 .

[32]  Bo Sun,et al.  Bedmap2: improved ice bed, surface and thickness datasets for Antarctica , 2012 .

[33]  David Pollard,et al.  Description of a hybrid ice sheet-shelf model, and application to Antarctica , 2012 .

[34]  J. Kutzbach,et al.  Northern Hemisphere forcing of Southern Hemisphere climate during the last deglaciation , 2013, Nature.

[35]  Nathan M. Urban,et al.  A comparison of Latin hypercube and grid ensemble designs for the multivariate emulation of an Earth system model , 2010, Comput. Geosci..

[36]  D. Pollard,et al.  Sea-level feedback lowers projections of future Antarctic Ice-Sheet mass loss , 2015, Nature Communications.

[37]  James R. Gattiker,et al.  The potential of an observational data set for calibration of a computationally expensive computer model , 2013 .

[38]  B. Scheuchl,et al.  Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith, and Kohler glaciers, West Antarctica, from 1992 to 2011 , 2014 .

[39]  John B. Anderson,et al.  Reconstruction of changes in the Weddell Sea sector of the Antarctic Ice Sheet since the Last Glacial Maximum , 2014 .

[40]  David G. Vaughan,et al.  West Antarctic Ice Sheet collapse – the fall and rise of a paradigm , 2008 .

[41]  D. Pollard,et al.  A glacial systems model configured for large ensemble analysis of Antarctic deglaciation , 2013 .

[42]  M. England,et al.  Antarctic contribution to meltwater pulse 1A from reduced Southern Ocean overturning , 2014, Nature Communications.

[43]  K. Calvin,et al.  The RCP greenhouse gas concentrations and their extensions from 1765 to 2300 , 2011 .

[44]  W. Peltier.  GLOBAL GLACIAL ISOSTASY AND THE SURFACE OF THE ICE-AGE EARTH: The ICE-5G (VM2) Model and GRACE , 2004 .

[45]  P. Clark,et al.  Closing the sea level budget at the Last Glacial Maximum , 2014, Proceedings of the National Academy of Sciences.

[46]  J. H. Mercer.  West Antarctic ice sheet and CO2 greenhouse effect: a threat of disaster , 1978, Nature.

[47]  P. Clark,et al.  Ice Sheet and Solid Earth Influences on Far-Field Sea-Level Histories , 2005, Science.

[48]  R. Alley,et al.  Dynamic (in)stability of Thwaites Glacier, West Antarctica , 2013 .

[49]  Gaël Durand,et al.  Grounding-line migration in plan-view marine ice-sheet models: results of the ice2sea MISMIP3d intercomparison , 2013, Journal of Glaciology.

[50]  R. DeConto,et al.  Contribution of Antarctica to past and future sea-level rise , 2016, Nature.

[51]  Murali Haran,et al.  Probabilistic calibration of a Greenland Ice Sheet model using spatially resolved synthetic observations: toward projections of ice mass loss with uncertainties , 2014 .

[52]  C. Ritz,et al.  Evolution of the Antarctic ice sheet throughout the last deglaciation: A study with a new coupled climate—north and south hemisphere ice sheet model , 2006 .

[53]  Philippe Huybrechts,et al.  Sea-level changes at the LGM from ice-dynamic reconstructions of the Greenland and Antarctic ice sheets during the glacial cycles , 2002 .

[54]  R. DeConto,et al.  Modeling Antarctic ice sheet and climate variations during Marine Isotope Stage 31 , 2012 .

[55]  D. Vaughan,et al.  Antarctic ice-sheet loss driven by basal melting of ice shelves , 2012, Nature.

[56]  D. Pollard,et al.  Calibrating an Ice Sheet Model Using High-Dimensional Binary Spatial Data , 2015, 1501.01937.

[57]  D. Hodgson,et al.  Retreat history of the East Antarctic Ice Sheet since the Last Glacial Maximum , 2014 .

[58]  John B. Anderson,et al.  Post-LGM deglaciation in Pine Island Bay, West Antarctica , 2012 .

[59]  D. Pollard,et al.  Calibrating an ice sheet model using high-dimensional non-Gaussian spatial data , 2015 .

[60]  Anne M. Le Brocq,et al.  A deglacial model for Antarctica: geological constraints and glaciological modelling as a basis for a new model of Antarctic glacial isostatic adjustment , 2012 .

[61]  D. Benn,et al.  Calving processes and the dynamics of calving glaciers , 2007 .

[62]  John B. Anderson,et al.  Geological record of ice shelf break-up and grounding line retreat, Pine Island Bay, West Antarctica , 2011 .

[63]  Hall,et al.  Past and Future Grounding-Line Retreat of the West Antarctic Ice Sheet. , 1999, Science.

[64]  Antony J. Payne,et al.  An improved Antarctic dataset for high resolution numerical ice sheet models (ALBMAP v1) , 2010 .

[65]  Eric Rignot,et al.  A Reconciled Estimate of Ice-Sheet Mass Balance , 2012, Science.

[66]  John B. Anderson,et al.  A community-based geological reconstruction of Antarctic Ice Sheet deglaciation since the Last Glacial Maximum , 2014 .

[67]  A. Vieli,et al.  A physically based calving model applied to marine outlet glaciers and implications for the glacier dynamics , 2010, Journal of Glaciology.

[68]  J. Oerlemans,et al.  A model study of the effect of climate and sea-level change on the evolution of the Antarctic Ice Sheet from the Last Glacial Maximum to 2100 , 2014, Climate Dynamics.

[69]  Radford M. Neal,et al.  A data-calibrated distribution of deglacial chronologies for the North American ice complex from glaciological modeling , 2012 .

[70]  L. Tarasov,et al.  How to evaluate model-derived deglaciation chronologies: a case study using Antarctica , 2013 .

[71]  D. Pollard,et al.  A 3-D coupled ice sheet – sea level model applied to Antarctica through the last 40 ky , 2013 .

[72]  F. Nitsche,et al.  Seismic stratigraphic record of the Amundsen Sea Embayment shelf from pre-glacial to recent times: Evidence for a dynamic West Antarctic Ice Sheet , 2013 .

[73]  G. Kuhn,et al.  New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum , 2014 .

[74]  A. Payne,et al.  Retreat of Pine Island Glacier controlled by marine ice-sheet instability , 2014 .

[75]  Matt A. King,et al.  A new glacial isostatic adjustment model for Antarctica: calibrated and tested using observations of relative sea‐level change and present‐day uplift rates , 2012 .

[76]  Daniel F. Martin,et al.  Adaptive mesh, finite volume modeling of marine ice sheets , 2013, J. Comput. Phys..

[77]  David M. Holland,et al.  The Response of Ice Shelf Basal Melting to Variations in Ocean Temperature , 2008 .

[78]  Jonathan M. Gregory,et al.  Calibrated prediction of Pine Island Glacier retreat during the 21st and 22nd centuries with a coupled flowline model , 2012 .